The most cost-effective kitchen counter surface medium is the decorative laminate composite construction. This material offers a wide range of performance advantages in terms of mar resistance, toughness/durability and ease of installation. The material is based on urea formaldehyde (UF)-bonded particle board clad with a thin sheet (60-100 mils) of a Kraft Paper composite laminate (the decorative laminate). At least two types of resin systems are used in the composite construction. The bulk of the composite is formed by saturating paper with an aqueous or polar solvent thinned phenolic resole solution using a continuous process in which the water and/or solvent are removed in a drying oven, allowing advancement (B-staging) of the resin impregnate to a degree of advancement such that a 5 stack (20-30 sheets) of the prepreg papers can be stack-press molded. This process is accomplished at 1000 psi and 270-350° F. for 5-30 minutes to give a highly crosslinked composite offering a broad range of environmental resistance. Surface performance in decorative laminates is achieved by topping the composite with 2-4 sheets of an amine resin (melamine formaldehyde (MF) or urea formaldehyde (UF)) Kraft prepreg prepared similarly to the phenolic version. The amine resin prepreg top sheet is Gravure-printed with the design and color scheme of choice. Many decorative laminates are embossed with a wood grain pattern and other designs using patterned platens. Bonding of the decorative laminate to the particle board is achieved using a contact adhesive. Delamination of the sheet from the supporting particle board is a major issue in these constructions. Board swell with moisture pickup is a major source of performance failure. Surface appearance of decorative laminates is their primary deficiency. With use and aging, they degenerate to a very unpleasant, dated appearance.
Another type of surface, solid surface synthetics, are polymer-bonded highly filled -composites offering a stone-like (heavy/solid) appearance and feel. Their density and modulus present a high “ring” when glass or ceramic dinnerware is handled on the bare surface. The first-in front-runner in this area was DuPont's Corian® product line. This product is 70% aluminum trihydrate (ATH) and a reactive polymer derived by dissolution of a high molecular weigh polymethylmethacrylate in methylmethacrylate. It is believed the reactive mixture is cured via a free radical mechanism using hemi-perester of maleic acid having a tertiary alkyl perestercomponent most commonly used is monotertiary butyl permaleic acid). Cocatalysts used along with this initiator are water soluble Group II metal salts which permit commercially acceptable cure rates in a range of filler systems. The filled composite is formed in cast cured blocks that are sliced into blank sheets for further customization by installers. The Corian® stock sheets are easily machined and finished into a variety of design options. Repair and refinishing are possible due to the machinability of the material. The filler system is uniform throughout the composite, allowing for refinishing without changing the appearance of article. The next generation of this product line is a 93% crushed quartz composite system marketed under the trademark Zodiac® by DuPont.